18 research outputs found
Validation of QSAR models for legislative purposes
OECD principles of validation of Quantitative Structure – Activity Relationships (QSAR) models for legislative purposes are given and explained. Reasons of their origination and development, like system REACH, are described. A basic impulse has come from some OECD countries followed by all (almost) other countries of the world
Toxicity of perfluorinated carboxylic acids for aquatic organisms
Toxicity of perfluorinated carboxylic acids with carbon chain C8 to C12 were tested with oligochaeta Tubifex tubifex. Toxicity was evaluated as the exposure time ET50 from onset of damage of the oligochaeta in saturated aqueous solutions. The ET50 fluctuated between 25 and 257 minutes. No statistically significant difference was found among the C8, C9 and C12 acids (ET50 between 143 and 257 minutes with large standard deviation). The acids with carbon chain C10 and C11 induced the effect significantly quicker (25 to 47 minutes). No acute toxicity measured in the three-minute test was observed in any case
Rychlý laboratorní test akutní toxicity ::zástava pohybu červů Tubifex tubifex
Manuscrito presentado al certamen de Obras de Poesía de 1798 cuyo tema era "Tragedias", con el lema en p. 1 y 2.: "Omne genus scripti gravitate tragedia vincit". Firmas del jurado y "N. H." en cub. Nota al lector en p. 3 y cub., y personajes en p. 6.Como asi, Esposa amada, spre. triste / Al llanto, y al dolor tu vida entregas?.... ...Que por si castigar quiere atrevido / Lo que solo à los Dioses les compete. / fin.Paginación y foliación original; port. enmarcada por orla; en bl. p. 4, h. 44v., 76v, 77-78 y 98